Director Resignation - send a letter to all the vendors and other clients stating the same and informing them

Hi, Ours is a Pvt. Ltd. firm, Out of the 4 directors 2 of us have purchased the shares and taken over the company. We want to send a letter to all the vendors and other clients stating the same and informing them that he is no longer the authorised signatory. Please help if anyone has this draft.

you have to pass a board resolution in a Board of Directors meeting and submit the certified copy of this resolution to all authorities. Draft is very simple and available on cite.
Regards,